This safety lamp is a patent model constructed by Joseph Defossez of Paris, France that received patent number 36,341 on September 2, 1862. In his patent filing, Defossez claimed as his invention “the pneumatic locking device in combination with the oil reservoir, top plate, and chimney” constructed to avoid the risk of mining explosions.
This safety lamp is a patent model constructed by William Roberts of Cincinnati, Ohio that received patent number 209,082 on October 15, 1878. In his patent filing, Roberts claimed “the combination of the transparent shell, surrounding the flame and provided with a cap or shell, and the wire-gauze chimneys, mounted upon said cap or shell, and arranged one within the other, so as to form an annular space or chamber between them.”
This oil-wick lamp is a patent model constructed by John O. Davies, John O. Jones, and Timothy Thomas of Plymouth, Pennsylvania that received patent number 220,582 on October 14, 1879. The patent claims as its invention “a miner's lamp consisting of an outer shell or cup, having a wick-tube and main wick combined with an oil-reservoir adapted to fit within said outer shell or cup, and having a perforated screw-cap in its bottom through which a supplemental feeding-wick passes.” The lamp kept the oil in a separate interior container to help prevent combustion.